Water based concentrated product forms of light stabilizers made by a heterophase polymerization technique

Abstract

The instant invention pertains to a concentrated aqueous dispersion of organic light stabilizers with a particle size of less than 1000 nm, prepared by heterophase radical polymerization of ethylenically unsaturated monomers in the presence of the light stabilizers, wherein the weight ratio of light stabilizer to polymeric carrier is greater than 50/100. Another aspect of the invention is a process for the preparation of such aqueous dispersions with high light stabilizer content. Aqueous dispersions prepared according to this process are useful ingredients for adhesives, aqueous emulsions of natural or synthetic rubbers, water based inks or a water based coating compositions, which are consequently also subjects of the invention.

1. A concentrated aqueous polymer dispersion of particles with an average particle size of less than 1000 nm said particles comprising
 a) a polymer carrier prepared by heterophase oil in water radical polymerization of at least one ethylenically unsaturated monomer selected from the group consisting of C 1 -C 18 acrylates, C 1 -C 18 methacrylates, acrylic acid, (meth)acrylic acid, styrene, vinyltoluene, hydroxy-functional acrylates, hydroxy-functional (meth)acrylates, acrylates derived from alkoxylated alcohols, (meth)acrylates derived from alkoxylated alcohols, multifunctional acrylates and multifunctional (meth)acrylates in the presence of 
 b) a non-polar organic light stabilizer, 1 wherein the non-polar organic light stabilizer has a water solubility of less than 1% by weight at room temperature and atmospheric pressure, 
 
       wherein the weight ratio of non-polar organic light stabilizer to polymer carrier is greater than 100 parts of light stabilizer per 100 parts of carrier and particle content of the aqueous polymer dispersion is more than 20% by weight based on the total weight of the aqueous polymer dispersion. 
     
     
       2. A concentrated aqueous polymer dispersion according to  claim 1  comprising additionally a non-ionic, cationic or anionic surfactant. 
     
     
       3. A concentrated aqueous polymer dispersion according to  claim 1  wherein the weight ratio of non-polar organic light stabilizer to polymer carrier is equal or greater than 120 parts per 100 parts. 
     
     
       4. A concentrated aqueous polymer dispersion according to  claim 1  wherein the average particle size is less than 500 nm. 
     
     
       5. A concentrated aqueous polymer dispersion according to  claim 1  wherein the non-polar organic light stabilizer is selected from the group consisting of a hydroxyphenyl benzotriazol UV-absorber, a hydroxyphenyl triazine UV-absorber, a hydroxybenzophenone UV-absorber, an oxalic anilide UV-absorber and a sterically hindered amine light stabilizer or mixtures thereof. 
     
     
       6. A concentrated aqueous polymer dispersion according to  claim 5  wherein the hydroxybenzophenone is of formula I 
       
         
           
           
               
               
           
         
         the 2-hydroxyphenylbenzotriazole is of formula IIa, IIb or IIc 
       
       
         
           
           
               
               
           
         
         the 2-hydroxyphenyltriazine is of formula III 
       
       
         
           
           
               
               
           
         
         and the oxanilide is of formula (IV) 
       
       
         
           
           
               
               
           
         
         in the compounds of the formula (I) v is an integer from 1 to 3 and w is 1 or 2 and the substituents Z independently of one another are hydrogen, halogen, hydroxyl or alkoxy having 1 to 12 carbon atoms; 
         in the compounds of the formula (IIa), 
         R 1  is hydrogen, alkyl having 1 to 24 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, cycloalkyl having 5 to 8 carbon atoms or a radical of the formula 
       
       
         
           
           
               
               
           
         
         R 4  and R 5  independently of one another are alkyl having in each case 1 to 5 carbon atoms, or R 4 , together with the radical C n H 2n+1−m , forms a cycloalkyl radical having 5 to 12 carbon atoms, 
         m is 1 or 2, n is an integer from 2 to 20 and 
         M is a radical of the formula —COOR 6  in which 
         R 6  is hydrogen, alkyl having 1 to 12 carbon atoms, alkoxyalkyl having in each case 1 to 20 carbon atoms in the alkyl moiety and in the alkoxy moiety or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, 
         R 2  is hydrogen, halogen, alkyl having 1 to 18 carbon atoms, and phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, and 
         R 3  is hydrogen, chlorine, alkyl or alkoxy having in each case 1 to 4 carbon atoms or —COOR 6  in which R 6  is as defined above, at least one of the radicals R 1  and R 2  being other than hydrogen; 
         in the compounds of the formula (IIb) 
         T is hydrogen or alkyl having 1 to 6 carbon atoms, 
         T 1  is hydrogen, chlorine or alkyl or alkoxy having in each case 1 to 4 carbon atoms, 
         n is 1 or 2 and, 
         if n is 1, 
         T 2  is chlorine or a radical of the formula —OT 3  or 
       
       
         
           
           
               
               
           
         
         if n is 2, T 2  is a radical of the formula 
       
       
         
           
           
               
               
           
         
         in which 
         T 3  is hydrogen, alkyl which has 1 to 18 carbon atoms and is unsubstituted or substituted by 1 to 3 hydroxyl groups or by —OCOT 6 , alkyl which has 3 to 18 carbon atoms, is interrupted once or several times by —O— or —NT 6 - and is unsubstituted or substituted by hydroxyl or —OCOT 6 , cycloalkyl which has 5 to 12 carbon atoms and is unsubstituted or substituted by hydroxyl and/or alkyl having 1 to 4 carbon atoms, alkenyl which has 2 to 18 carbon atoms and is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, or a radical of the formula —CH 2 CH(OH)-T 7   
       
       
         
           
           
               
               
           
         
         T 4  and T 5  independently of one another are hydrogen, alkyl having 1 to 18 carbon atoms, alkyl which has 3 to 18 carbon atoms and is interrupted once or several times by —O— or 
         —NT 6 -, cycloalkyl having 5 to 12 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety or hydroxyalkyl having 2 to 4 carbon atoms, 
         T 6  is hydrogen, alkyl having 1 to 18 carbon atoms, cycloalkyl having 5 to 12 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, 
         T 7  is hydrogen, alkyl having 1 to 18 carbon atoms, phenyl which is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, or —CH 2 OT 8 , 
         T 8  is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 8 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, 
         T 9  is alkylene having 2 to 8 carbon atoms, alkenylene having 4 to 8 carbon atoms, alkynylene having 4 carbon atoms, cyclohexylene, alkylene which has 2 to 8 carbon atoms and is interrupted once or several times by —O—, or a radical of the formula —CH 2 CH(OH)CH 2 OT 11 OCH 2 CH(OH)CH 2 — or —CH 2 —C(CH 2 OH) 2 —CH 2 —, 
         T 10  is alkylene which has 2 to 20 carbon atoms and can be interrupted once or several times by —O—, or cyclohexylene, 
         T 11  is alkylene having 2 to 8 carbon atoms, alkylene which has 2 to 18 carbon atoms and is interrupted once or several times by —O—, 1,3-cyclohexylene, 1,4-cyclohexylene, 1,3-phenylene or 1,4-phenylene, or 
         T 10  and T 6 , together with the two nitrogen atoms, are a piperazine ring; 
         in the compounds of formula (IIc) 
         R′ 2  is C 1 -C 12 alkyl and k is a number from 1 to 4 
         in the compounds of the formula (III) 
         u is 1 or 2 and r is an integer from 1 to 3, the substituents 
         Y 1  independently of one another are hydrogen, hydroxyl, phenyl or halogen, halogenomethyl, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 18 carbon atoms, alkoxy having 1 to 18 carbon atoms which is substituted by a group —COO(C 1 -C 18 alkyl); 
         if u is 1, 
         Y 2  is alkyl having 1 to 18 carbon atoms, phenyl which is unsubstituted or substituted by hydroxyl, halogen, alkyl or alkoxy having 1 to 18 carbon atoms; 
         alkyl which has 1 to 12 carbon atoms and is substituted by —COOH, —COOY 8 , —CONH 2 , —CONHY 9 , —CONY 9 Y 10 , —NH 2 , —NHY 9 , —NY 9 Y 10 , —NHCOY 11 , —CN and/or —OCOY 11 ; 
         alkyl which has 4 to 20 carbon atoms, is interrupted by one or more oxygen atoms and is unsubstituted or substituted by hydroxyl or alkoxy having 1 to 12 carbon atoms, alkenyl having 3 to 6 carbon atoms, glycidyl, cyclohexyl which is unsubstituted or substituted by hydroxyl, alkyl having 1 to 4 carbon atoms and/or —OCOY 11 , phenylalkyl which has 1 to 5 carbon atoms in the alkyl moiety and is unsubstituted or substituted by hydroxyl, chlorine and/or methyl, —COY 12  or —SO 2 Y 13 , or, 
         if u is 2, 
         Y 2  is alkylene having 2 to 16 carbon atoms, alkenylene having 4 to 12 carbon atoms, xylylene, alkylene which has 3 to 20 carbon atoms, is interrupted by one or more —O— atoms and/or is substituted by hydroxyl, —CH 2 CH(OH)CH 2 —O—Y 15 —OCH 2 CH(OH)CH 2 , —CO—Y 16 —CO—, —CO—NH—Y 17 —NH—CO— or —(CH 2 ) m —CO 2 —Y 16 —OCO—(CH 2 ) m , in which 
         m is 1, 2 or 3, 
         Y 8  is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 18 carbon atoms, alkyl which has 3 to 20 carbon atoms, is interrupted by one or more oxygen or sulfur atoms or —NT 6 - and/or is substituted by hydroxyl, alkyl which has 1 to 4 carbon atoms and is substituted by —P(O)(OY 14 ) 2 , —NY 9 Y 10  or —OCOY 11  and/or hydroxyl, alkenyl having 3 to 18 carbon atoms, glycidyl, or phenylalkyl having 1 to 5 carbon atoms in the alkyl moiety, 
         Y 9  and Y 10  independently of one another are alkyl having 1 to 12 carbon atoms, alkoxyalkyl having 3 to 12 carbon atoms, dialkylaminoalkyl having 4 to 16 carbon atoms or cyclohexyl having 5 to 12 carbon atoms, or Y 9  and Y 10  together are alkylene, oxaalkylene or azaalkylene having in each case 3 to 9 carbon atoms, 
         Y 11  is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms or phenyl, 
         Y 12  is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms, phenyl, alkoxy having 1 to 12 carbon atoms, phenoxy, alkylamino having 1 to 12 carbon atoms or phenylamino, 
         Y 13  is alkyl having 1 to 18 carbon atoms, phenyl or alkylphenyl having 1 to 8 carbon atoms in the alkyl radical, 
         Y 14  is alkyl having 1 to 12 carbon atoms or phenyl, 
         Y 15  is alkylene having 2 to 10 carbon atoms, phenylene or a group -phenylene-M-phenylene- in which M is —O—, —S—, —SO 2 —, —CH 2 — or —C(CH 3 ) 2 —, 
         Y 16  is alkylene, oxaalkylene or thiaalkylene having in each case 2 to 10 carbon atoms, phenylene or alkenylene having 2 to 6 carbon atoms, 
         Y 17  is alkylene having 2 to 10 carbon atoms, phenylene or alkylphenylene having 1 to 11 carbon atoms in the alkyl moiety, and 
         Y 18  is alkylene having 2 to 10 carbon atoms or alkylene which has 4 to 20 carbon atoms and is 3 interrupted once or several times by oxygen; 
         in the compounds of the formula (IV) x is an integer from 1 to 3 and the substituents L independently of one another are hydrogen, alkyl, alkoxy or alkylthio having in each case 1 to 22 carbon atoms, phenoxy or phenylthio. 
       
     
     
       7. A concentrated aqueous polymer dispersion according to  claim 5  wherein the sterically hindered amine is selected from the group consisting of bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl)succinate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, linear or cyclic condensates of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate, 1,1′-(1,2-ethanediyl)-bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decan-2,4-dione, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, linear or cyclic condensates of N,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of 2-chloro-4,6-bis(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane, the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidin-2,5-dione, 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensation product of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, a condensation product of 1,2-bis(3-aminopropylamino)ethane and 2,4,6-trichloro-1,3,5-triazine as well as 4-butylamino-2,2,6,6-tetramethylpiperidine; N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimide, N-(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimide, 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4,5]decane, a reaction product of 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospiro [4,5]decane und epichlorohydrin, 1,1-bis(1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl)-2-(4-methoxyphenyl)ethene, N,N-bis-formyl-N,N-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine, diester of 4-methoxy-methylene-malonic acid with 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly[methylpropyl-3-oxy-4-(2,2,6,6-tetramethyl-4-piperidyl)]siloxane and reaction product of maleic acid anhydride-α-olefin-copolymer with 2,2,6,6-tetramethyl-4-aminopiperidine, 1,2,2,6,6-pentamethyl-4-aminopiperidine, 2,4-bis[N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)-N-butyl-amino]-6-(2-hydroxyethyl)amino-1,3,5-triazine, 1-(2-Hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine, 5-(2-ethylhexanoyl)oxymethyl-3,3,5-trimethyl-2-morpholinone or a compound 
       
         
           
           
               
               
           
         
       
       in which n is from 1 to 15. 
     
     
       8. A process for the preparation of a concentrated aqueous polymer dispersion with an average particle size of less than 1000 nm comprising the step of polymerizing at least one ethylenically unsaturated monomer in the presence of a non-polar organic light stabilizer by heterophase radical polymerization; 
       wherein the weight ratio of non-polar organic light stabilizer to polymer carrier formed from the ethylenically unsaturated monomer is greater than 100 parts of light stabilizer per 100 parts of polymer carrier. 
     
     
       9. A process according to  claim 8  comprising the steps of
 a) dissolving, emulsifying or dispersing a non-polar organic light stabilizer in at least one ethylenically unsaturated monomer; 
 b) preparing a conventional oil in water emulsion of said light stabilizer dissolved, emulsified or dispersed in at least one ethylenically unsaturated monomer; 
 c) homogenizing the conventional emulsion to a miniemulsion wherein the droplets of the organic phase have an average diameter below 1000 nm 
 d) polymerizing the miniemulsion by adding a polymerization initiator; 
 
       wherein the weight ratio of non-polar organic light stabilizer to polymer carrier formed from the ethylenically unsaturated monomer is greater than 100 parts of light stabilizer per 100 parts of polymer carrier. 
     
     
       10. A polymer powder obtained by vaporizing the volatile components of the concentrated aqueous polymer dispersion according to  claim 1 . 
     
     
       11. A composition stabilized against thermal, oxidative or light-induced degradation which comprises,
 (a) an organic material susceptible to thermal, oxidative or light induced degradation, and 
 (b) a concentrated aqueous polymer dispersion according to  claim 1 . 
 
     
     
       12. A composition according to  claim 11  wherein the amount of component b) is from 0.1 to 40% by weight based on the weight of the solid content of component a). 
     
     
       13. A composition according to  claim 11  wherein the organic material is a recording material. 
     
     
       14. A composition according to  claim 13  wherein the recording material is a photographic material or an ink jet material. 
     
     
       15. A composition according to  claim 13  wherein the recording material is a printed material containing the concentrated aqueous polymer dispersion in an overprint varnish. 
     
     
       16. A composition according to  claim 11  wherein the organic material (a) is an adhesive, an aqueous emulsion of a natural or synthetic rubber, a water based ink or a water based coating. 
     
     
       17. A powder coating composition stabilized against thermal, oxidative or light-induced degradation comprising
 a) a solid binder material; and 
 b) a polymer powder according to  claim 10 . 
 
     
     
       18. A composition stabilized against thermal, oxidative or light-induced degradation comprising
 a) a thermoplastic polymer and 
 b) a polymer powder according to  claim 10 . 
 
     
     
       19. A method of stabilizing an organic material susceptible to thermal, oxidative or light induced degradation, which comprises incorporating therein a stabilizingly effective amount of a concentrated aqueous polymer dispersion according to  claim 1 . 
     
     
       20. A method of stabilizing a powder coating against thermal, oxidative or light-induced degradation, which comprises incorporating therein a stabilizingly effective amount of a polymer powder according to  claim 10 . 
     
     
       21. A concentrated aqueous polymer dispersion according to  claim 1  wherein the dispersion contains 20% by weight or more of the light stabilizer b) based on the total weight of the dispersion.